Computing device.



D. H. HAWTHORNE.

COMPUTlNG DEVICE.

APPLICATION FILED JUNE 5.1916.

1 206,703. Putentd Nov. 28, 1916.

2 SHEETSSHEET I.

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a-ttoznexao DAVID H. HAWTHORNE, 0F atNTHON,

BTW it COMPUTING DEVICE.

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Specification of Letters Patent. ii gmtggsd, Nay, 23, T5916,

' Application filed June 5, 1916. Serial No. 101,808.

To all whom it may concern Be it known that I, DAVID H. HAW- rnonnn, a citizen of the United States, residing at Anthon, in the county of Voodbury and State of Iowa, have invented certain new and useful Improvements in-Computing Devices; and I do declare the following to be a full, clear, and exact description of the inventi0'n,,such as will enable others skilled in the art to which it appertains to make and use the same.

My invention which relates to improvements in computing devices, has for its principal object to provide a simply constructed, inexpensive and etlicient device for -determining the exact number of days which have elapsed between the day on which the computation is made and any day not more than three hundred and sixty-five days previous thereto. The invention, however, is adapted equally well for other purposes which will be clearly explained as the descriptive mat ter proceeds.

lVith the foregoing general object in View, the invention resides in certainnovel features of construction and in unique combinations of parts to be hereinafter fully described and claimed, the descriptive matter being supplemented by the accompanying drawings which constitute a part of this application and in which:

Figure 1 is a front elevation of the improved device with the lower roller set for computing in the month of April; Fig. 2 is a vertical transverse section taken on the plane of the line 2-2 of Fig. 1; Fig. 3 is a plan view of the covering of the roller; and Fig. 4 is a similar view of that employed on the lower -roller.

In specifically describing the structure shown in the drawings above briefly de scribed, similar characters will be. employed to designate corresponding partsthroughout the several views and reference will be herein made to the numerous elements by their respective indices. To this end, the numeral 1 designates a casing which pref erably consists of a solid bottom 2, solid substantially triangular ends 3 and sheet metal sides and top 4 covered with any suitable material 5 which will preferably give the appearance of leather. These features, however, are immaterial and may be varied as occasion may demand. It is essential, however, that the front of the casing be formed with upper and lower horizontal slots 6 and 7 respectively, and that upper and lower rollers 8 and "9 be mounted within the casing 1 to be'partly exposed through said slots. Journals 10 extend from the ends of the upper and lower rollers through suitable bearing openings in the ends 3 of the casing l and are provided on their outer ends with knobs 11 whereby they may be rotated at will, lock nuts 12 being preferably though not necessarily threaded on certain of the journals whereby they may be locked against rotation should this be expedient.

A scale 13 extends along the upper slot 6, said scale having" thirty-one numbers representing thirty-one month days, the left hand end of said scale terminating in spaced relation to this end of the slot as shown clearly in Fig. 1. The scale 13 cooperates with thirty-one rows 14 of numbers extending circumferentially around the upper roller 8, each of said rows consisting of thirty-one numbers representing month days. An additional row 15 extends circumferentially around the roller 8 to the left of the scale 13 and likewise consists of thirtyone numbers designating month days. Certain of the numbers of the rows 14 will be printed in black ink while others will preferably be red, the area on which the black numbers occur being shaded in the drawings for the sake of illustration (see Fig. 3), this being essential for reasons to be described. All of the numbers will be located precisely as shown in the last named figure in order that the device may operate in the required manner. A second scale 16 extends along the lower slot 7 and consists of twelve legends representing the twelve months, said legends cooperating with twelve rows of numbers 17 which extend circumferentially around the lower roller 9 and designate year days, these numbers being arranged as depicted in Fig. at. A row of legends 18 extends circumferentially around the roller 9 to the left of the scale 16, said legends representing the twelve months.

In use, the lower roller 9 is set in the morning of any date so that the present month appears at the left end of the lower slot '1'. he upper roller is also turned until the day of the month appears at the left end of the upper slot 6. For example, on April 7, the lower roller is turned until April appears while the upper one is positioned to end of the upper roller.

expose 7 at the left The device is now in condition for operation.

To compute the number of days from any date which has passed to the present date,

take the number in sight on the/lower roller directly under the month desired to compute from and add to it the number in sight on the upper roller directly under the day of said month or subtract if the day number appears in red, and the result will be the exact number of days which have elapsed between the previous and present dates. For example, from July l to April 7 is found to be two hundred and seventy seven days, by adding to the number on lower roller under the month of July of the scale 16 (which number is 274) the number in sight on upper roller under the figure 4- of the scale 13,

making a total of two hundred and seventy seven days from July 4 to April 7. Had the previous date been July 11 instead of July 4,

4 should be subtracted from the number two hundred and seventy four in sight under July, as the number in sight on upper roller below the figure 11 of the scale 13 appears in red ink. The number of days between any other dates may be found in the same manner. The number of days between the present date and any future date may be obtained if desired by setting the device so that the future date desired appears at the left of the rollers, after which the operator will proceed in the manner described above. This is a secondary use, however, as it is intended primarily to be employed in banks in -which the lapsed days of their obligations are figured to the present date. A third and also auxiliary use of the improved device is to determine on what date a. given number of days from a given date will fall. This is accomplished by turning the lower roller until the number nearest the given number of days appears below the month from which the computation is being made. 'lVith this number at hand, it is only necessary to add or subtract the difference between it and the stated number of days to or from the cor responding date in the month then in sight at the left of the roller. The result will be the desired date. For example, it is desired to find on whatday sixty days from April 7 will fall. The lower roller turned until the number 61 (the nearest number to appears below the month of April on the scale 16. By subtracting (the diiference between the stated number of days and the number appearing under April) from the 'date of the present day (7). we find that sixty days from this date will fall on June 6, since June appears at the left end of the lower roller. The upper roller remains idle while this computation is being made.

From the foregoing, taken in connection with the accompanying drawings, the constructionand manner of operation of the improved device will be readily understood and it will be obvious that regardless of the extremely simple construction employed, the improved computer will be highly efficient and will possess a wide range of uses. In leap years, a different arrangement of numbers will be substituted for those on the lower roller but it is not deemed necessary to illustrate such arrangement herein.

I claim:

A computing. system designed primarily for determining the elapsed days between any given date and the day on which the computation is made, said system comprising a chart having thirty-one vertically extending rows of horizontally alined numbers representing month days, each row containing thirty one numbers, a horizontal scale having thirty-one numbers representing month days for cooperation with said thirtyone rows. an additional row of monthdays on the chart distinguished from the other rows and disposed to the left thereof, said additional row containing thirty one numbers in horizontal alinement with the others and representing month days; a second chart having twelve vertically extending rows of horizontally alined numbers representing year days, each of said rows containing twelve numbers, a second horizontal scale having twelve legends cooperating with said twelve rows of numbers and representing the twelve months, and a row of legends on said second chart to the left of the others, in horizontal alinement with the numbers thereof, and representing the twelve months, half of the numbers in the thirty-one cohunns of the first-named chart being distinguished from those. of the other half, the dividing line between the two sets of numbers extending obliquely from one corner of the chart to the other.

In testimony whereof l have hereunto set any band in presence of two subscribing witnesses.

DAVID H. lTAlVTl-TORNE. V i tnesses W anmen W. Sorinms, G. W. FrrcnNnu. 

